Saturday, February 05, 2011


Spent a couple of hours fiddling with the RS-485 converter but was not able to remotely control the MallinCam using Stephan Lalonde's MC Control software.

Initial testing was done with an old Apple Macintosh serial cable with the matching mini DIN 8-pin connector as what is used on the MallinCam. I performed continuity tests on the cable to map the pins to the wire colours.
  • 1 - red
  • 2 - orange
  • 3 - brown
  • 4 - green
  • 5 - yellow
  • 7 - red
  • 8 - green
The pin numbers correspond to the MallinCam documentation. They are opposite / reversed what I found on some Apple pages.

I had to decipher what DATA + and DATA - meant in the MallinCam notes in relation to the 485-232 converter which used very different labelling.
  • 1 - T+
  • 2 - T-
  • 3 - R+
  • 4 - R-
The clearest information I found was on the JAT Observatory web site. But no matter which configuration I tried, nothing worked. The 485 converter he used however had more appropriate pin-outs: D+, D-, GND, 5VDC+. Simple.

I was concerned about the interconnections inside the Apple Macintosh cable. I think it is specifically a modem cable. So I did total grunge loose wires directly from pin 1 and pin 3 of the camera. Still no joy.

I even dug out my old portable modem to ensure my COM1 port on the John Smallberries PC was working properly.

Looks like this 232-485 converter is not working. I'll have to return it to Sayal.

I'll see if people still make the custom cable with the integrated 485 conversion. I believe it will actually come in cheaper...

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